JP7637475B2 - Vibration-damping studs - Google Patents

Description

The present invention relates to vibration-damping studs.

The following Patent Document 1 shows a bending column damper in which a shear panel is attached between a bending column made of H-shaped steel that is divided into upper and lower halves.

JP 2005-133433 A

The bending column damper in Patent Document 1 functions as a seismic damper when the shear panel yields during an earthquake. During an earthquake, this bending column damper is subjected to axial force in addition to shear force. Therefore, there is a possibility that the shear panel will buckle due to the axial force, and will not be able to fully exert its shear strength.

Taking the above facts into consideration, the present invention aims to provide a vibration-damping stud in which the axial force acting on the column is less likely to act on the shear yielding portion that undergoes shear deformation.

The vibration-damping stud of claim 1 comprises a steel upper stud joined to an upper beam and having a base plate at its lower end, a steel lower stud joined to a lower beam below the upper stud, disposed at a distance from the upper stud and having a top plate at its upper end, a shear yielding portion joined to the lower end surface of the upper stud and the upper end surface of the lower stud and having a shear yield strength smaller than that of the steel material constituting the upper stud and the lower stud, a lower end of the portion arranged above the base plate is welded to the upper end surface of the base plate, and an upper end of the portion arranged below the top plate is welded to the lower end surface of the top plate, and the base plate and the top plate are welded to each other. an axial force transmission rib, the upper end of which is located between the upper studs and the lower studs, is welded to the lower end surface of the base plate, and the lower end of which is located between the base plate and the top plate is welded to the upper end surface of the top plate, and the axial force transmission rib is provided parallel to the flanges of the upper stud and the lower stud from above the base plate to below the top plate, and transmits the axial force acting on the upper stud to the lower stud, and the portion located above the base plate is welded to the web of the upper stud in the vertical direction, and the portion located below the top plate is welded to the web of the lower stud in the vertical direction.

According to the vibration-damping stud of claim 1, a shear yielding portion is disposed between the upper stud joined to the upper beam and the lower stud joined to the lower beam. Therefore, when the upper stud and the lower stud are displaced relatively in the lateral direction during an earthquake, a shear force acts on the shear yielding portion.
The shear yielding section has a smaller shear yield strength than the steel material that constitutes the upper and lower studs. Therefore, the shear yielding section undergoes shear deformation before the upper and lower studs, and is therefore able to absorb earthquake energy.

In addition, this vibration-damping stud has an axial force transmission rib that extends from the upper stud to the lower stud. During an earthquake, vertical and horizontal shaking causes axial forces to act on the upper and lower studs, but the axial force is transmitted between the upper and lower studs via this axial force transmission rib. This prevents axial force from being input to the shear yielding section.

Therefore, the shear yielding portion is less likely to buckle due to axial force, which makes it easier for the shear yielding portion to absorb earthquake energy through shear deformation.
The vibration-damping stud of claim 2 is the vibration-damping stud of claim 1, wherein the axial force transmission rib comprises two upper ribs as a portion located above the base plate, two lower ribs as a portion located below the top plate, and two central ribs welded to the lower end surface of the upper stud and the upper end surface of the lower stud as a portion located between the base plate and the top plate, and the shear yield portion is provided between the two central ribs.
The vibration-damping stud of claim 3 is the vibration-damping stud of claim 1, wherein the shear yielding portion comprises a plate-shaped panel extending along the in-plane direction of a column-beam structure including the beam, a first reinforcing member extending along the horizontal direction and arranged in contact with one face of the panel, and a second reinforcing member extending along the vertical direction and arranged in contact with the other face of the panel.

The vibration-damping stud of claim 4 is the vibration-damping stud of claim 1, wherein the upper stud is rigidly connected to the upper beam and the lower stud is rigidly connected to the lower beam, and the shear yield portion is located at a position including an intermediate height between the upper beam and the lower beam.

When the upper and lower beams are displaced relative to one another during an earthquake, a bending moment acts on the vibration-damping studs. The upper studs are rigidly connected to the upper beams, and the lower studs are rigidly connected to the lower beams. For this reason, the bending moment acting on the vibration-damping studs is smallest in the middle part between the upper and lower beams.

In the vibration-damping stud of claim 4 , the shear yielding portion is located at the position where the bending moment is smallest. Therefore, bending moment is unlikely to act on the shear yielding portion. This makes it easier for the shear yielding portion to shear deform and absorb earthquake energy.

A vibration-damping stud according to claim 5 is the vibration-damping stud according to claim 1 or 2, wherein the shear yielding portion undergoes shear yielding when an external force larger than the primary design seismic force of the building occurs.

In the vibration-damping stud of claim 5 , the shear yielding portion does not shear yield when subjected to an external force equal to or less than the building's primary design earthquake force. In other words, even if the vibration-damping stud experiences an internal stress equal to or less than the stress calculated by the building's allowable stress calculation, the shear yielding portion does not shear yield and maintains its elasticity. This allows the vibration-damping stud to function as an earthquake-resistant member in small to medium-sized earthquakes, and as a vibration-damping member in large-scale earthquakes.

According to the present invention, the axial force acting on the vibration-damping stud is less likely to act on the shear yielding portion that undergoes shear deformation.

FIG. 2 is an elevational view of a vibration-damping stud according to an embodiment of the present invention. FIG. 2 is a perspective view showing a shear yielding portion in a vibration-damping stud according to an embodiment of the present invention. FIG. 2 is an elevational view showing a method for installing a vibration-damping stud according to an embodiment of the present invention. FIG. 1A is an elevation view showing a modified example of a vibration-damping stud according to an embodiment of the present invention, in which the upper end and main body of the upper stud are integrally formed, and the lower end and main body of the lower stud are integrally formed, and FIG. 1B is an elevation view showing a modified example of (A) in which a joining plate is further provided. FIG. 11 is an elevation view showing a modified example in which flanges of the upper stud and the lower stud are used as axial force transmission ribs in a vibration-damping stud according to an embodiment of the present invention.

The vibration-damping stud 20 according to an embodiment of the present invention will be described below with reference to the drawings. Components indicated with the same reference numerals in each drawing are the same components. However, unless otherwise specified in the specification, each component is not limited to one, and may exist in multiples. Also, explanations of configurations and reference numerals that are duplicated in each drawing may be omitted. Note that the present invention is not limited to the following embodiment, and can be implemented with appropriate modifications, such as omitting configurations or replacing them with different configurations, within the scope of the purpose of the present invention.

Figure 1 shows a vibration-damping stud 20 (hereinafter referred to as stud 20) according to an embodiment of the present invention. Stud 20 is a stud joined to each of the vertically adjacent beams 10 (upper beam 10A and lower beam 10B) in a building with a column-beam frame. Stud 20 is designed not to support long-term loads.

The direction indicated by the arrow X in FIG. 1 is the direction (horizontal direction) that coincides with the installation direction of the beam 10, and the direction indicated by the arrow Z is the direction (vertical direction) that coincides with the extension direction of the partition 20. In addition, both the X direction and the Z direction are directions along the in-plane direction of the column-beam structure that includes the beam 10.

The upper beam 10A and the lower beam 10B are adjacent H-shaped steel beams on the same structural plane. The upper beam 10A is the upper beam, and the lower beam 10B is the lower beam. The upper beam 10A and the lower beam 10B may be made of reinforced concrete or steel-reinforced concrete.

<Vibration-damping studs>
The studs 20 are comprised of upper studs 22 and lower studs 24, each of which is made of H-shaped steel, which is ordinary steel. The upper stud 22 is rigidly joined to the upper beam 10A and protrudes downward from the upper beam 10A. Similarly, the lower stud 24 is rigidly joined to the lower beam 10B and protrudes upward from the upper beam 10A. The upper studs 22 and lower studs 24 are disposed at the same position in a plan view.

(Upper stud)
The upper stud 22 has an upper end 22A (so-called bracket) that is integrated with the upper beam 10A, and a main body 22B that is joined to the upper end 22A using a splice plate P. The splice plate P joins the flanges and webs of the upper end 22A and main body 22B, respectively. A base plate 22C is joined to the lower end of the main body 22B. The base plate 22C is welded to each of the web and flanges of the main body 22B.

(Lower stud)
Similarly, the lower stud 24 has a lower end 24A (so-called bracket) that is integrated with the lower beam 10B, and a main body 24B that is joined to the lower end 24A using a splice plate P. The splice plate P joins the flanges and webs of the lower end 24A and main body 24B to each other. A top plate 24C is joined to the upper end of the main body 24B. The top plate 24C is welded to each of the web and flange of the main body 24B, and is disposed spaced apart in the vertical direction from the base plate 22C. In other words, the upper stud 22 and the lower stud 24 are disposed spaced apart in the vertical direction.

(Axial force transmission rib)
The axial force transmission rib 40 is a reinforcing material provided from the upper stud 22 to the lower stud 24, which are arranged at a distance in the vertical direction. The axial force transmission rib 40 transmits axial force between the upper stud 22 and the lower stud 24. This axial force is the axial force that acts during an earthquake.

The axial force transmission rib 40 is composed of an upper rib 42, a lower rib 44, and a central rib 46. In addition, the axial force transmission rib 40 is formed using the same steel material as the steel material forming the upper stud 22 and the lower stud 24.

The upper ribs 42 are provided along the Z direction and are welded to the web of the main body 22B of the upper stud 22 and to the base plate 22C. Two upper ribs 42 are provided spaced apart in the X direction (two when the column-beam structure is viewed from the front). The upper ribs 42 are also provided on both sides of the web of the main body 22B (i.e., four in total).

The lower ribs 44 are provided along the Z direction and are welded to the web of the main body 24B and the top plate 24C of the lower stud 24. Two lower ribs 44 are provided spaced apart in the X direction (two when the column-beam structure is viewed from the front). The lower ribs 44 are also provided on both sides of the web of the main body 24B (i.e., a total of four).

The central rib 46 is provided along the Z direction and is welded to the base plate 22C of the upper stud 22 and the top plate 24C of the lower stud 24. Two central ribs 46 are provided spaced apart in the X direction.

The upper rib 42, the lower rib 44, and the central rib 46 are all located at the same position in the X direction. In other words, the upper rib 42, the lower rib 44, and the central rib 46 are each located on an extension of the other in the Z direction.

(Shear yielding section)
A shear yielding portion 30 is formed between the base plate 22C and the top plate 24C. The shear yielding portion 30 is also provided between the two central ribs 46.

The shear yield section 30 is located at a position including the midpoint between the upper beam 10A and the lower beam 10B (a position straddling the center line CL).

As shown in FIG. 2, the shear yielding section 30 is composed of a panel 32 and reinforcements 34 and 36. Note that in FIG. 2, the upper stud 22 is omitted in order to explain the configuration of the shear yielding section 30.

The panel 32 is a plate-like member arranged along the X and Z directions (in other words, the in-plane direction of the beam-column structure) at a position that passes through the axis of the studs 20 (upper studs 22 and lower studs 24), and is formed using steel material with a lower shear yield strength than the steel material that forms the upper studs 22 and lower studs 24.

The upper and lower end faces of the panel 32 are welded to the base plate 22C and the top plate 24C, respectively. In other words, the panel 32 is joined to the lower end face of the upper stud 22 and the upper end face of the lower stud 24, for example, by welding. A shear force is input to the panel 32 when the upper beam 10A and the lower beam 10B are displaced relative to each other. The panel 32 will shear yield when an external force greater than the building's primary design seismic force occurs.

In this embodiment, the panel 32 is made of a steel material (e.g., low yield point steel) that has a lower shear yield "stress" than the steel material that forms the upper stud 22 and the lower stud 24. However, the embodiment of the present invention is not limited to this.

For example, the panel 32 may be made of a steel material having the same shear yield stress as the steel material forming the upper stud 22 and the lower stud 24. In this case, the thickness of the panel 32 can be made thinner than the thickness of the H-shaped steel webs forming the upper stud 22 and the lower stud 24, thereby making the shear yield strength relatively small.

In this way, any desired shear yield strength can be obtained by adjusting the shear yield stress of the steel material used for panel 32 and the thickness of panel 32. Any desired shear yield strength can also be obtained by adjusting the width (length along the X direction) of panel 32.

The reinforcing members 34, 36 are each formed to have a smaller shear yield strength than the steel material forming the upper stud 22 and the lower stud 24, or to have a shear yield strength equivalent to that of the steel material forming the upper stud 22 and the lower stud 24. In addition, the reinforcing members 34, 36 are each formed to have a larger shear yield strength than the steel material forming the panel 32.

The reinforcing member 34 is formed into a plate shape with both ends welded to the two central ribs 46. The reinforcing member 34 is also provided along the X direction in the center of the panel 32 in the Z direction, and is disposed in contact with one surface of the panel 32.

The upper and lower ends of the reinforcing member 36 are welded to the base plate 22C (see FIG. 1) and the top plate 24C, respectively, and are formed into a plate shape. The reinforcing member 36 is provided along the Z direction in the center of the panel 32 in the X direction, and is disposed in contact with the other surface of the panel 32 (the surface opposite to the surface in contact with the reinforcing member 34). The reinforcing members 34 and 36 may each be welded or glued to the panel 32.

<How to install vibration-damping studs>
The studs 20 are formed by assembling the parts assembled in a factory to the column-beam frame on-site. Specifically, the unit U1 formed of the main body 22B of the upper stud 22, the base plate 22C, the main body 24B of the lower stud 24, the top plate 24C, the axial force transmission rib 40, and the shear yielding portion 30 is assembled in the factory and then transported to the construction site of the building.

At the building construction site, after a slab (not shown) is laid across the upper beams 10A and lower beams 10B, unit U1 is placed between the upper end 22A of the upper stud 22 and the lower end 24A of the lower stud 24, and unit U1 is joined to the upper end 22A and the lower end 24A.

The unit U1 may be placed between the upper end 22A and the lower end 24A before the slab is laid. In this case, the unit U1 is temporarily fixed to the upper beam 10A and the lower beam 10B, and is permanently fixed (the bolts that secure the splice plate (see Figure 1) are permanently tightened) after the slab is formed.

<Action and Effects>
1, in the stud 20 according to the embodiment of the present invention, a shear yielding portion 30 is disposed between the upper stud 22 joined to the upper beam 10A and the lower stud 24 joined to the lower beam 10B. Therefore, when the upper stud 22 and the lower stud 24 are displaced relative to each other in the lateral direction (X direction) during an earthquake, a shear force acts on the shear yielding portion 30.

The panel 32 (see Figure 2) that forms the shear yield section 30 has a smaller shear yield strength than the steel material that constitutes the upper stud 22 and the lower stud 24. Therefore, the panel 32 undergoes shear deformation before the upper stud 22 and the lower stud 24, and is able to absorb earthquake energy.

The studs 20 are also provided with axial force transmission ribs 40 that extend from the upper studs 22 to the lower studs 24. During an earthquake, vertical axial forces act on the upper studs 22 and lower studs 24 due to vertical and horizontal shaking, but the axial force is transmitted between the upper studs 22 and lower studs 24 via the axial force transmission ribs 40. This prevents the axial force from being input to the panel 32.

Therefore, the panel 32 is less likely to buckle due to axial force. This allows the panel 32 to undergo sufficient shear deformation, making it easier to absorb earthquake energy.

When the upper beam 10A and the lower beam 10B are displaced relative to each other during an earthquake, a bending moment acts on the stud 20. The upper stud 22 is rigidly connected to the upper beam 10A, and the lower stud 24 is rigidly connected to the lower beam 10B. For this reason, the bending moment acting on the stud 20 is smallest in the middle part between the upper beam 10A and the lower beam 10B (near the center line CL).

In the stud 20, the shear yielding section 30 is located at the position where the bending moment is smallest (the position straddling the center line CL). Therefore, bending moment is unlikely to act on the shear yielding section 30. This allows the panel 32 to undergo sufficient shear deformation, making it easier to absorb earthquake energy.

In addition, in the case of the studs 20, the panels 32 will shear yield if an external force greater than the building's primary design seismic force is applied. In other words, the panels 32 will not shear yield if an external force equal to or less than the building's primary design seismic force is applied. In other words, when the studs 20 are subjected to internal stresses equal to or less than the stress calculated by the building's allowable stress calculation, the panels 32 will not shear yield and will maintain their elasticity. This allows the studs 20 to function as earthquake-resistant members in small- to medium-sized earthquakes, and as vibration-damping members in large-scale earthquakes.

In addition, reinforcing members 34, 36 are provided in contact with the panel 32 on the stud 20. This prevents the panel 32 from buckling in the out-of-plane direction (Y direction). Therefore, the panel 32 can undergo sufficient shear deformation, making it easier to absorb earthquake energy.

In this way, the studs 20 can absorb earthquake energy by providing shear yielding sections 30, which helps prevent damage to the building's column-beam structure. In addition, compared to using vibration control devices such as dampers, the vibration control performance of the building can be improved at a lower cost.

<Other embodiments>
In the above-described embodiment, the upper stud 22 is formed of an upper end portion 22A, a main body portion 22B, and a base plate 22C, and the lower stud 24 is formed of a lower end portion 24A, a main body portion 24B, and a top plate 24C, but the embodiments of the present invention are not limited to this.

For example, as shown in FIG. 4(A), instead of the upper end portion 22A and the main body portion 22B, a main body portion 22D that integrates them may be provided. Also, instead of the lower end portion 24A and the main body portion 24B, a main body portion 24D that integrates them may be provided.

In this case, the unit U2 formed by the base plate 22C of the upper stud 22, the top plate 24C of the lower stud 24, the central rib 46 of the axial force transmission rib 40, and the shear yielding portion 30 is assembled in a factory and transported to the building construction site. The unit U2 is welded to the main body portion 22D, the main body portion 24D, the upper rib 42, and the lower rib 44.

As shown in FIG. 4B, joining plates 22E and 24E may be provided at the lower end of main body 22D and the upper end of main body 24D, respectively. In this case, by bolting joining plate 22E to base plate 22C and bolting joining plate 24E to top plate 24C, the amount of welding work on-site can be reduced.

In addition, in the above-described embodiment, as shown in FIG. 1, there are two upper ribs 42, two lower ribs 44, and two central ribs 46 (two when the column-beam structure is viewed from the front), but the embodiment of the present invention is not limited to this.

For example, as shown in FIG. 5, a configuration may be used in which only one upper rib 42 and one lower rib 44 are provided. In this case, one of the central ribs 46 (central rib 46A) is positioned on the extension line of the flanges of the upper stud 22 and the lower stud 24. This allows the flanges of the upper stud 22 and the lower stud 24 to be used as axial force transmission ribs.

In addition, in the above-described embodiment, the upper stud 22 is rigidly connected to the upper beam 10A, and the lower stud 24 is rigidly connected to the lower beam 10B, but the embodiment of the present invention is not limited to this. For example, the joining method and joining force of the upper stud 22 and the lower stud 24 to the upper beam 10A and the lower beam 10B are arbitrary, and the joining method and joining force may be different from each other.

In this case, the height position at which the bending moment is minimum in the stud 20 changes. Specifically, the height position at which the bending moment is minimum approaches the part where the joining force is small. In this case, it is preferable to also move the shear yielding portion 30 appropriately.

In addition, in the above-described embodiment, the panel 32 is assumed to yield in shear when an external force greater than the building's primary design seismic force occurs, but the embodiment of the present invention is not limited to this. In other words, the shear strength of the panel 32 can be set to any value.

For example, the shear strength of the panel 32 may be a strength at which the panel 32 shear yields when an external force equal to or less than the allowable design stress acts on the building. This allows the shear yielding section 30 to demonstrate vibration control performance even in small to medium-sized earthquakes.

10A Upper beam (upper beam)
10B Lower beam (lower beam)
20 Vibration-damping stud 22 Upper stud 24 Lower stud 30 Shear yielding portion 40 Axial force transmission rib

Claims (5)

a steel upper stud connected to the upper beam and having a base plate at its lower end;
a lower stud made of steel, which is joined to a lower beam below the upper stud and spaced apart from the upper stud, and which has a top plate at an upper end thereof;
a shear yield portion that is joined to a lower end surface of the upper stud and an upper end surface of the lower stud and has a shear yield strength smaller than that of the steel material constituting the upper stud and the lower stud;
an axial force transmission rib, which is provided from above the base plate to below the top plate in parallel with the flanges of the upper stud and the lower stud, and which transmits the axial force acting on the upper stud to the lower stud, the lower end of which is welded to the upper end surface of the base plate, the upper end of which is welded to the lower end surface of the top plate, the upper end of which is welded to the lower end surface of the base plate, and the lower end of which is welded to the upper end surface of the top plate,
having
The upper portion of the base plate is welded to the web of the upper stud along the vertical direction;
The lower portion of the top plate is welded to the web of the lower stud along the vertical direction.
Vibration-damping studs. The axial force transmission rib is
As a portion disposed above the base plate , two upper ribs;
As a portion disposed below the top plate , two lower ribs;
As a portion disposed between the base plate and the top plate, two central ribs are welded to a lower end surface of the upper stud and an upper end surface of the lower stud;
Equipped with
The shear yield portion is
Located between the two central ribs,
2. The vibration-damping stud of claim 1. The shear yield portion is
A plate-shaped panel along an in-plane direction of a column-beam frame including the beam;
a first laterally extending stiffener disposed adjacent one face of the panel;
A second reinforcing member arranged in contact with the other surface of the panel along the vertical direction;
Equipped with
2. The vibration-damping stud of claim 1. the upper stud is rigidly connected to the upper beam;
The lower stud is rigidly connected to the lower beam;
The shear yield portion is provided at a position including an intermediate height between the upper beam and the lower beam.
2. The vibration-damping stud of claim 1. The vibration-damping stud according to claim 1 or 2, in which the shear yielding portion shears when an external force greater than the building's primary design seismic force occurs.